PROM1 and glioblastoma: The receptor for human epidermal growth factor type 2 (HER2), IL-13 receptor alpha 2 (IL-13Rα2), CD133, B7-H3 (type I transmembrane protein), ganglioside (GD2), and human epidermal growth factor receptor variant III (EGFR vIII) are the principal targets exploited in GBM currently.